Add content-type and filename params for file upload

[MrRTi]

Currently all files are sent with type application/octet-stream. This update will add ability to pass content_type and filename as args if needed

Actual:

{
    "message": {
      ...
        "file": {
            ...
            "type": "application/octet-stream"
        },

Expected:

{
    "message": {
      ...
        "file": {
            ...
            "type": "image/jpeg"
        },

[abrom]

Apologies for the delay in actioning this @MrRTi

Update has been released in v0.2.4